Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Algebra

Question:

If $(x-\frac{1}{x})^2= 12$, what is the value of $(x^2-\frac{1}{x^2})$, given that x > 0?

Options:

$6\sqrt{2}$

$8\sqrt{3}$

$6\sqrt{3}$

$8\sqrt{2}$

Correct Answer:

$8\sqrt{3}$

Explanation:

If $(x-\frac{1}{x})^2= 12$

then, $(x-\frac{1}{x})$ = \(\sqrt {12}\) =  2\(\sqrt {3}\)

and $(x+\frac{1}{x})$ =  \(\sqrt {12 + 4}\) = 4

The value of $(x^2-\frac{1}{x^2})$ = 4 × 2\(\sqrt {3}\) = $8\sqrt{3}$